OSP for Printed Circuit Boards PCBs

OSP :-

OSP; Organic Solderability Preservative's have made great progress in recent years. They are now capable of multiple solder passes, and have probably the longest shelf life of all the std ROHS compliant leadfree finishes. Unlike silver or tin the OSP doesn't form an intermetalic layer that results in the short shelf life and poor solderability of the other metallic finishes. It's also extremely green environmentally in comparison with the other common leadfree finishes, which suffer from either more toxic waste or substantially higher energy consumption. After much consideration Macdermid's M-Coat OSP is currently our default and favourite leadfree finish. OSP is projected to be used on 558 million sq ft of circuit boards in 2008 second fiddle to HASL at 737 million sq ft. It's best thought of as a an almost invisible protective lacquer on the surface of the board. In reality the surface of the board is treated with an acidic cleaner followed by a persulphate microetch to render to clean and increase the surface area, at which point it is then given it's organic coating. The process is selective whereby a reaction take place with the copper on the PCB to form the coating, only a very minimal amount is deposited onto the base laminate.

M-Coat Data Sheet


Organic Metal	Board Finish's